“Moreover, some vice presidents were more influential than others, depending on their skill, standing, relationship with the president and other governmental figures, and the need for their talents, among other factors,” Goldstein writes.

“Notwithstanding these differences, all six vice presidents since 1977 were integral to the White House. The persistence of this pattern through three Democratic and three Republican presidencies, each with different leadership structures and styles, suggests that this change in the vice presidency reflects an institutional change and isn’t simply the result of an idiosyncratic president or vice president.”